55 and 1/2% can be written as a decimal: 0.555. To see what number is about 55.5% of 23, multiply 0.555 by 23. Answer: 12.765 or about 13.

一个nother route is to say that 55.5% is about half of 23. Half of 23 is 11.5. Since 55.5% is greater than 50%, 13 is the logical choice instead of 11.

We need to find expressions for fifty percent ofxand for thirty percent of the positive difference betweenxandy. Then, we can set these two expressions equal to each other and determine the ratio ofxtoy.

Fifty percent ofxis equal to one-half ofx, which is the same as multiplyingxby 0.50.

50% ofx= 0.5x

百分之三十的积极的区别xandymeans that we need to multiply the positive difference betweenxandyby thirty percent. Becausex>y, the positive difference betweenxandyis equal tox–y. We then need to take thirty percent of the quantityx–y. Remember that to convert from a percent to a decimal, we move the decimal two spaces to the left. Therefore, 30% = 0.30. We can now multiply this by (x –y).

30% ofx–y= 0.30(x–y)

Now, we set the two expressions equal to one another.

0.5x= 0.30(x–y)

Distribute the right side.

0.5x= 0.3x– 0.3y

The ratio ofxtoyis represent byx/y. Thus, we want to group thexandyterms on opposite sides of the equations, and then divide both sides byy.

0.5x= 0.3x– 0.3y

Subtract 0.3xfrom both sides.

0.2x= –0.3y

Divide both sides by 0.2

x= (–0.3/0.2)y

Divide both sides byyto findx/y.

x/y= (–0.3/0.2) = –1.5.

Because the answers are in fractions, we want to rewrite –1.5 as a fraction. We can write –1.5 as –1.5/1 and then mutiply the top and bottom by 2.

(–1.5/1)(2/2) = –3/2

The answer is –3/2

We are told that 50% ofxis equal to 25% ofy. We need to represent these two pieces of information as algebraic expressions. We can convert 50% and 25% to decimals by moving the decimals two places to the left. Thus, 50% = 0.50, and 25% = 0.25. To find 50% ofx, we multiplyxby 0.50. In other words, 50% ofx= 0.50x. Likewise, 25% ofy= 0.25y. We now set 0.50xand 0.25yequal to one another.

0.50x= 0.25y

Let's divide both sides by 0.25 to get rid of decimals.

2x=y

Next, we are told that 40% ofyis equal to 60% ofz. We will represent 40% and 60% as 0.40 and 0.60, respectively. Thus, we can write the following equation:

0.40y= 0.60z

Ultimately, we are asked to findxas a percentage ofz. This means we want to find an equation withxandz, but noty. If we solve foryin the second equation, and then substitute this value into the first, we can eliminatey.

Let's take the equation 0.40y= 0.60zand divide both sides by 0.40.

y= 1.5z

Now, we can take 1.5zand substitute this foryin the first equation.

2x= 1.5z

In order to findxas a percent ofz, we must solve forxin terms ofz. This means we must divide both sides of the equation by 2.

x= 0.75z

xis 0.75 timesz. We can represent 0.75 as 75%, because in order to convert from a decimal to a percent, we need to move the decimal two spaces to the right. Therefore, ifx= 0.75z, thenx= 75% ofz.

The answer is 75.

In order to answer the question, we must find out the percent of each class that has signed Tom's petition, and compare it to 8%.

Freshmen:have signed.

Sophomores:have signed.

Juniors:have signed.

Seniors:have signed.

Tom has the necessary signatures from members of the top three classes, but he cannot get on the ballot yet because he has not gathered enough signatures from freshmen.